Is your sandesh or rosogolla laced with nitric acid' If there is any truth in the complaints made by consumer groups, the chhana, or cottage cheese, used to make these sweets is curdled with nitric acid instead of citric acid or calcium lactate and this could lead to serious stomach ailments. The enforcement branch of the city police, along with civic authorities, raided chhana patti in Bowbazar on Tuesday evening after the complaints were made.

Both the police and the civic authorities maintained that there is no need to panic. This was a precautionary exercise undertaken by the authorities.

Officers said at the Calcutta Municipal Corporation (CMC) that deputy commissioner of the enforcement branch Rajiv Kumar sought the civic body’s help to carry out a raid on chhana patti. Food inspectors accompanied the police and collected at random 12 samples of cottage cheese from three shops. The samples were sent to the CMC laboratory for chemical analyses. The report of the public analyst is expected in about a week’s time.

The officer on special duty (health) of the CMC, Atanu Mukherjee, said if any acid other than citric is found in the cottage cheese, a case will be started against the offenders in the municipal magistrate’s court. “So far, there is nothing to suggest that there is anything harmful in the samples we collected on Tuesday,” Mukherjee said.

“Nitric acid is harmful and unfit for human consumption. All acids are sour and can curdle milk. Sweets made from chhana using nitric acid can cause gastritis and other stomach ailments, like ulcers,” said the superintendent of civic food laboratory Subrata Bose.

Cottage cheese is the basic raw material from which sweets are made, and Bowbazar is the biggest wholesale market in the city. Officers said about 5,000 quintals of chhana are sold at Bowbazar and Sovabazar daily, and the bulk comes from the villages of Kalna, Katwa, Hasnabad and Midnapore. Civic health officers said nitric acid is cheaper and the chhana it yields is firmer, remains fresh longer and is odourless.

Deputy commissioner Kumar said he had received complaints on this score from some consumer groups. “We can say for certain that nitric acid was used to make the cottage cheese only after we receive the analysis report from the CMC laboratory,” he said. There are over 5,000 sweet shops in Calcutta.